1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display having an improved display area.
2. Description of the Related Art
In general, an active matrix type-liquid crystal display; AM-LCD) device is thin, so that it is often used in various display devices. In this AM-LCD device, one thin film transistor(TFT) is provided as a switching element for each pixel, so that individual pixel electrodes are independently driven. The contrast is therefore not reduced based upon the reduction of a duty ratio, and also the angle of visibility is not reduced, even when the capacity of display is increased to increase the number of lines.
FIG. 1 shows a plane view of an array substrate in the conventional AM-LCD.
Referring to FIG. 1, a gate line 21 and a data line 22 are arranged in the shape of matrix on a cell region 20 of an array substrate 10. ESD(ElectroStatic Discharge) protection parts 31 and 32 are disposed on an outside substrate 10 of the cell region 20, respectively. The ESD protection parts 31 and 32 are connected to input portions of the gate line 21 and the data line 22, respectively, thereby protecting the gate line 21 and the data line 22 from ESD.
However, since the area of the cell region 20 is limited due to the ESD protection parts 31 and 32, it is limited to improve display area.
It is therefore an object of the present invention to provide a liquid crystal display device which can protect a cell region from ESD and improve a display area, for solving the problems in the conventional art.
To accomplish this above object, a liquid crystal display device according to the present invention, includes: a cell region arranged on the overall region of an array substrate; a gate line and a data line arranged in the shape of matrix on the cell region; an ESD protection part disposed at one side of a cross portion of the gate line and the data line, the ESD protection part protecting the gate line and the data line from ESD; and a thin film transistor disposed at the other side of the cross portion, the thin film transistor acting as a switching element.
Furthermore, in the ESD protection part, one side of the gate line is in contact with a source/drain metal pad, one side of the data line is in contact with a gate metal pad, and the other side of the gate line is in contact with a source/drain metal layer. Preferably, the distance between the ESD protection part and the thin film transistor is xc2xc to ⅓ of a pitch size.
Moreover, the ESD protection part includes first and second transistors and both the first and second transistors are a NMOS transistor. Here, a gate of the first transistor is connected to a source thereof, a drain of the first transistor is connected to a gate of the second transistor, and the gate of the second transistor is connected to a source thereof.
Additional object, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.